Your Digest for Sunday, Mar 03, 2024 01:59 PM


    - aminophylline is a complex of (theophylline and ethylenediamine) 

Source

Pneumoconioses

Asbestosis Silicosis Berylliosis
Primary from mining;
Secondary exposure from using in manufacturing
Sand blasting etc Electronics manufacture
Fibrous form of Magneiusm Silicate SiO2 crystals ?Beryllium
Two Forms: Chrysolite - white asbestos, serpentien fibers - less harmful.
Crosydolite - blue asbestos, straight fibers, more harmful
Pleural plaques 20 to 30 years after exposure - most on rib associated surfaace of pleura
Benign effusions
Diffuse pleural thickening
Mesotheliomas
Bronchial Carcinomas
SiO2 crystals persist cause necrosis of phagocytosing macrophages -> enzymes release -> lung damage. (cessation of exoposure doens't hald lung damage);
Macrophage toxicity predisposes to post primary tuberculosis.
Lower lobe predilection Upper lobe fibrosis with lymph nodes which can calcify Upper lobe predilection.
asbestosis.png SilicosisUpperLobeEggShellCalcification.png

Causes of dominant R wave in V1

#2016GM-APR/Q01
RVH, Right sided Heart, RBB, Posterior MI

[!INFO] Summary

LBBB RBBB
Always pathological Can be benign
Causes LAD No effect on axis
Affects MI diagnosis No effect on MI diagnosis

normalQRScomplex.png

[!TIP] Mnemonic: It seems that increase in ventricular afterload can cause ipsilateral bundle branch blocks.
? cause of LAD in LBBB?
?is it because The counterbalancing effect of RV depolarization on the axis is lost as the RV depolarizes later??
Verapamil is a suitable alternative for adenosine if it it contraindicated.

[!INFO] AV nodal blocking drugs
Source: Harrison's
Mnemonic: AV nodal Blocking drugs : AVB -> Adenosine, verapamil, beta blockers (after trying vagal maneuvers)
(+? others)
AVNodeBlockingDrugs.png


[!INFO] Mnemonics:
Adenocarcinoma : Acchis
SQCs : Smokers
4. Diagnosis: By anti-P/Q-type voltage-gated calcium channel (VGCC) antibody testing and high frequency RNS (repetitive nerves stimulation)
5. Targeted therapy for symptomatic LEMS with 3,4-diaminopyridine is usually first line.
6. Refractory cases : immunosuppressants and plasma exchange.



HypercalcemiaSymptomsMnemonic.png

[!TIP] Hypercalcemia: Abdominal groans, psychich moans and renal stones.


Comparison of ABPA, EGPA and Hypersensitivity pneumonitis

Allergic bronchopulmonary aspergillosis
[[passMedicine Summaries#Hypersensitivity pneumonitis (HP)|Hypersensitivity Pneumonitis]]

Features ABPA
EGPA (Churg strauss)
Hypersensitivity Pneumonitis
Presentation Presents as poorly controlled asthma Can present with Difficult to control asthma
Clinical pearls Can be unmasked with monteleukast
Blood and serology Eosinophilia,
IgE levels always positive. Skin prick test for aspegillus is +ve.
Eosinophilia +
pANCA +ve
No eosinophilia
CD8+ predominant BAL aspirate
CXR Xray changes – migratory but persistent infiltrates. Proximal bronchiectasis, Upper lobe fibrosis if recurrent, Flitting pulmonary infiltrates CXR – non specific CT – centrilobular nodules.
Clinical features Fever, wheeze, cough Vasculitic features: mononeuritis multiplex, Rapidly proliferating glomerulonephritis, Tender subcutaneous nodules Acute: Fever, cough, No wheezing Chronic: SOB, fatigue, dyspnoea Crackles
Treatment Steroids + itraconazole + voriconazole Responds well to steroids Steroids + allergen avoidance

Complications of ileal resection


| Metformin | Biguanide | Insulin sensitiztion Reduce hepatic gluconeogenesis.It activates AMPK (AMP activated protein kinase) | GI side effects Lactic acidosis (risk in renal/liver/heart failure – contrindications) No weight gain May reduce apetite, STOP when eGFR < 30 | Reduced GI B12 absorption The usual first line agent, can be combined with other | Lower FBS by about 50 mg/dL Lowers HbA1C by about 1% |
Mechanism of action: Increases intracellular c-AMP potentiated insulin secretion.




After initial detection on the FBC, the investigation of choice is immunophenotyping by flow cytometry to reveal cell surface markers typical of CLL, including CD5, CD19 and CD20.

Background physiology of lymphocytes

LymphocyteOrigin.png
Source-YouTube
Source-YouTube
Source-YouTube

MHC I MHC II
Present on ALL nucleated cells Presenton APCs
Binds CD8 receptor Binds CD4 receptors
Stimultes Cytotoxic T cells Stimulates T helper cells

Natural killer cells

Chronic lymphocytic leukemia features


GVHD can occur after allogenic haemotopoietic cell transplantation or with solid organs containing lymphoid tissue. (Bowel transplant was one example)
GVHD arises when immune cells transplanted from a non-identical donor graft into the recipient (host), recognize the host cells as "foreign," thereby initiating a graft-versus-host reaction.

    - **Dermatitis** - painful, pruritic rash.  (not vessicles like in the mnemonic) 
- ![RashOfGraftVsHostDisease.png](RashOfGraftVsHostDisease.png)

  1. Progressive multifocal leukoencephalopathy (PML) ^13ac5c

#2016GM-OCT/Q29

Leishmaniasis: spectrum of disease.

Leishmaniasis has a wide spectrum of disease

At one end of the spectrum, mucosal leishmaniasis (ML) and leishmaniasis recidivans (LR) are caused by oligoparasitic disease associated with a marked cellular immune response.
The center of the spectrum consists of localized cutaneous leishmaniasis (LCL), which is the most common clinical presentation.
At the opposite end of the spectrum, diffuse cutaneous leishmaniasis (DCL) is caused by polyparasitic disease with a predominance of parasitized macrophages and no granulomatous inflammation.

Cutaneous leishmaniasis

This is the commoner form in Sri Lanka.
Symptoms:

Diffuse cutaneous

Musocal leishmaniasis

Visceral leishmaniasis

Post-kala-azar dermal leishmaniasis (PKDL) is a complication of visceral leishmaniasis (VL); it is characterised by a macular, maculopapular, and nodular rash in a patient who has recovered from VL and who is otherwise well.

PKDLKalaAzar.png


  1. Hypercoaulable states can occur, specially with membranous nephropathy.
  2. Sepsis is a major cause of death due to loss of immunoglobulin -> pneumococcal infections
  3. Lipid abnormalities -> increased cardiovascular risk.
  4. ACEi / ARB are indicated for all patients with nephrotic range proteinuria.
  1. ?monoclonal deposition disease (presents with nephrotic range proteinuria

[!INFO] What "Effacement" means:
"Errasing, dissapearance". (like effacement of the cervix)

In this phenomenon, the normal interdigitated foot processes are finally reorganized into a broad flattened process like a paddle. The morphological process of the foot process effacement has not fully elucidated. Source
footProcesseffacementImageWhatIs.png

FSGS

FSGS is more likely with inflammatory conditions like SLE - PasTest

Primary FSGS Secondary FSGS
Sometimes responds to steroids, failure of steroids is common. Other immunosuppresants are used. Usually poor response to steroids. ACEi are better
Presents as massive proteinuria, haematuria and hypertension. Can be caused by any process which reduces functioning number of nephrons (eg. nephrectomy)
(nephrectomy, hypertension, gross obesity, IgA nephropathy, HIV, CMV, EBV)

FSGS pathology:

Source

proposedMechanismOfFSGS.png

in embryonic mice, parietal epithelial cells can migrate to the visceral layer and replace damaged podocytes (Right) but in the older mice, such replacement can't occur and results in sclerosis. (left)

FSGSHistology.png
Source

Minimal change Vs. FSGS

[!TIP]
MCD and FSGS are like cousins; FSGS is the evil cousin.

c | Electron microscopy image showing subepithelial electron-dense deposits (spikes)(black arrows) and basement membrane material between the electron-dense deposits (white arrows; 4,800×).



Common problems in geriatric medicine are

Falls

#2016GM-OCT/Q25
RiskFactorsForFalls.png


chestLeadViewsHeart.png

Leads with ST segment elevations Affected myocardial area Occluded coronary artery (cuprit)
V1–V2 Septal Proximal LAD.
V3–V4 Anterior LAD.
V5–V6 Apical / Lateral Distal LAD, LCx or RCA.
I, aVL Lateral LCx.
II, aVF, III Inferior 90% RCA. 10% LCx.

Right ventricular infarction

ECG-posterior-infarction-in-V2.jpg.webp
Posterior-leads-V7-V8-V9-ECG-placement.jpg.webp
- Isolated posterior wall STEMI is uncommon.
- Tall R waves in V1 and V2 are reciprocals of Q waves in the posterior wall.

Post MI prognosis

Killip class Features 30 day mortality
I No clinical signs heart failure 6%
II Lung crackles, S3 17%
III Frank pulmonary oedema 38%
IV Cardiogenic shock 81%


Coeliac disease

BCD + PRSTUvW
Bacterial overgrowh, Coeliac disease, Dermatitis herpetiformis
Parasites, Resection, Sprue, Tropical Srpue, Uv = radiation, Whipples

Symptoms

Complications

CoeliacDiseaseEndoscopy.png
coeliacDiseaseNoVilliCryptHyperplasia.png


AlcoholSafeUnits.png

[!INFO] It takes 1 hour to process 1 unit



PolycysticKidneyDisease.png

type 1 PCKD Type 2 PCKD
85% of cases 15% of cases
Presents earlier with renal failure

📑Management of PCKD


[!TIP] Mnemonic: Don't confuse with PSC - PBC has 'cirrhosis' in the name -> liver tissue is inolved -> interlobular bile ducts are involved.
#2016GM-OCT/Q30
enterohaemorrhagic (EHEC) (aka STEC - shiga toxin producing E coli)

But there are actually 5 types.

  1. ETEC causes watery diarrhea in resource-limited settings and is commonly found in food and water in areas without adequate sanitation
  2. EPEC (enteropathogenic) was the first E. coli pathotype identified as a causative agent of watery diarrhea primarily in infants and young children in resource-limited settings
  3. EAEC (enteroaggregative) is a causative organism of acute and chronic watery diarrhea in resource-limited and resource-rich regions
  4. EHEC/STEC produces Shiga-toxin and includes serotypes O157:H7, as well as others
  5. EIEC-induced diarrheal illness is uncommon due

Hook worm

Necator americanus ("American murderer")
and ancylostoma ceylonicum
HookWormAncylostoma.png


Bradykinin

[!TIP] Mnemonic : BPH - bradykinin, prostaglandin and histamine act together.

ClostridiumDifficileStoolSamples.png
| | |

[!INFO] Up to 1 year post op for valve replacement, staph epidermidis >> staph aureaus.
[[aetiologicAgentsInfectiveEndocarditis.png]]

HACEK denotes Haemophilus species, Actinobacillus actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens and Kingella kingae.


- They are also some of the oldest antiepileptics. Newer drugs have better pharmacokinetics. 
- The narrow spectrum AEDs mostly work for specific types of seizures (such as focal, absence, **or** myoclonic seizures). 
- Broad spectrum AEDs additionally have some effectiveness for a *wide variety of seizures* (focal **plus** absence myoclonic seizures).

AntiepilepticSpectrum.png
Source
- Mnemonic: cOllECtIvE (COLLECTIVE IS SIMILAR TO 'BROADLY') (LeCo-VoLT)
BroadSpectrumAEDsMnemonic.png


Anxiety


If > 8 hours since ingection, NAC is given rather than methionine.

[!INFO] Paracetamol
1,4,8,16
Gastric lavage 1 hour.
Activated charcoal 4 hours. Levels also at 4 hours.
Before 8 hour, methionine can be given and is as effective as NAC.
After 8 hours, give NAC.
Liver damange unlikely if NAC started within 8 hours.

Criteria for liver transplantation

King's College Hospital criteria for liver transplantation (paracetamol liver failure)

almost identical to cinchonism (quinine toxicity).


Non alcoholic fatty liver disease (NASH)/(NALFD)


Feature Hepatitis B Hepatitis C
Epidemiology est. 220 million carriers est. 70 million carriers
Virus type DNA SS-RNA
Transmission Vertical(during birth) is common
Hep B in children is a main issue
Vertical transmission is rare
Blood + products Blood + products, needle sharing
Vaccine Present Rapid mutations -> No vaccine
Clinical course Acute: 70% subclinical (anicteric)
 30% icteric hepatitis
1% - fulminant hepatitis
Overall, in vast majority disease is self limited.
Acute: Asymptomatic but 10% will have flu like symp.
Overall about 25% will clear the infection spontaneously.
Chronic: 5% of acute infection becomes chronic Chronic: 90% of asymptomatic acute infection becomes chronic.
50% of symptomatics become chronic.
Chronic infection 4 phases:
HBeAg+, normal ALT, High DNA
HBeAg+, fluctuating ALT, fluctuating DNA
HBeAg-, normal ALT, low DNA
HBeAg-, fluctuating ALT, fluctuating DNA
Outcome of chronic infection 15% cirrhosis of which 20% decompensate and 5% get HCC. Cirrhosis is slowly progressive
15% get cirrhosis at 20 years of which 5% decompensate per year, 1% get HCC per year and 4% die per year.
HDV relationship Coinfection -> usually self limited; but⬆ risk of acute liver failure (compared to superinfection).
No increased risk of chronic infection.
None
Superinfection: ALL develop chronic HBV
can present as acute severe hepatitis.
None
Chronic HDV -> rapid progression to cirrhosis. None
HCC association Accounts for 50% of HCC; mostly after onset of cirrhosis. accounts for 20% of HCC; but HCC only occurs after cirrhosis has developed.
⬆viral load increases risk
Immune complexe mediated extrahepatic phenomena are less common in Hep C than in Hep B, except for essential mixed cryoglobulinaemia
Extrahepatic manifestations "Serious Pirates Plundered Nine gold diamond chests" Arthritis, myalgia, Sjogrens, kerato. conj. sicca, Mooren corneal ulcer, porphyria cutanea tarda, lichen planus, asymptomatic mixed cryoglobulinaemia (Type II cgb), membranoproliferative glomerulonephritis
Initially cryoglobulinaemia was described in hepaitits B. Also causes a "mixed cryoglublinaemia". Essential mixed Cryoglobulinaemia is commoner in Hep C:
Mnemonic: C-C. "mixed" means Rheumatoid factor, IgG, Hep C virus RNA and complement.
Treatment 90% clearance rate with treatment!

Painful Painless
Corneal abrasion Lens dislocation
Keratitis Vitreous haemorrhage
Acute Glaucoma Acute maculopathy
Hyphema Retinal detachment
Endophthalmitis Retinal artery occlusion
Anterior Uveitis Retinal Vein occlusion
Optic Neuritis Ischemic optic neuropathy

Hypersensitivity pneumonitis (HP)

Source

Symptoms

Acute Subacute Chronic
Occurs in previously sensitized individuals
Fever, chills (unlike asthma), cough, chest tightness exertional dyspnea, productive cough, fatigue, and weight loss, no fever.
4 - 8 hours after exposure Months to years
Occurs with high level antigen exposure Occurs with low level antigen exposure (like a bird owner)
Physical: fine crackes, NO WHEEZING Can be complicated with cor pulmonale / respiratory failure.
Airway obstruction is unusual Can cause a restrictive pattern

Investigations
CXR - Non specific.
HRCT - profuse, poorly defined centrilobular micronodules is the most characteristic findings. Fibrosis in Chronic HP.
BAL - Lymphocytosis with CD8+ predominance. (lymphocytosis with CD4+ predominant is seen in sarcoidosis)

Treatment:

Side effects of chemotherapy drugs

ToxicityBearChemtherapeuticDrugs.png

cytotoxicAgentsAndSummaries.png